Stored sperm differs from ejaculated sperm by proteome alterations associated with energy metabolism in the honeybee Apis mellifera.

Sperm are exposed to substantially different environments during their life history, such as seminal fluid or the female sexual tract, but remarkably little information is currently available about whether and how much sperm composition and function alters in these different environments. Here, we used the honeybee Apis mellifera and quantified differences in the abundance and activity of sperm proteins sampled either from ejaculates or from the female's sperm storage organ. We find that stored and ejaculated sperm contain the same set of proteins but that the abundance of specific proteins differed substantially between ejaculated and stored sperm. Most proteins with a significant change in abundance are related to sperm energy metabolism. Enzymatic assays performed for a subset of these proteins indicate that specific protein activities differ between stored and ejaculated sperm and are typically higher in ejaculated compared to stored sperm. We provide evidence that the cellular machinery of sperm is plastic and differs between sperm within the ejaculate and within the female's storage organ. Future work will be required to test whether these changes are a consequence of active adaptation or sperm senescence and whether they alter sperm performance indifferent chemical environments or impact on the cost of sperm storage by the female.However, these changes can be expected to influence sperm performance and therefore determine sperm viability or sperm competitiveness for storage or egg fertilization.

Proteins within the seminal fluid are crucial to keep sperm viable in the honeybee Apis mellifera.

Seminal fluid is a biochemically complex mixture of glandular secretions that is transferred to the females sexual tract as part of the ejaculate. Seminal fluid has received increasing scientific interest in the fields of evolutionary and reproductive biology, as it seems a major determinant of male fertility/infertility and reproductive success. Here we used the honeybee Apis mellifera, where seminal fluid can be collected as part of a male's ejaculate, and performed a series of experiments to investigate the effects of seminal fluid and its components on sperm viability. We show that honeybee seminal fluid is highly potent in keeping sperm alive and this positive effect is present over a 24h time span, comparable to the timing of the sperm storage process in the queen. We furthermore show that the presence of proteins within the seminal fluid and their structural integrity are crucial for this effect. Finally, we activated sperm using fructose and provide evidence that the positive effect of seminal fluid proteins on sperm survival cannot be replicated using generic protein substitutes. Our data provide experimental insights into the complex molecular interplay between sperm and seminal fluid defining male fertility and reproductive success.

Defining the phosphite-regulated transcriptome of the plant pathogen Phytophthora cinnamomi.

Phosphite, an analog of phosphate is used to control oomycete diseases on a wide range of horticultural crops and in native ecosystems. In this study, we investigated morphological and transcriptional changes induced in Phytophthora cinnamomi by phosphite. Cytological observations revealed that phosphite caused hyphal distortions and lysis of cell walls and had an adverse effect on hyphal growth. At the molecular level, the expression levels of 43 transcripts were changed. Many of these encoded proteins involved in cell wall synthesis, or cytoskeleton functioning. The results of both the microscopic and molecular investigations are consistent with phosphite inhibiting the function of the cytoskeleton and cell wall synthesis.

Incidence and etiologies of complicated parapneumonic effusions in children, 1996 to 2001.

BACKGROUND: The incidence and causative organisms associated with complicated parapneumonic effusions in children with community-acquired pneumonia are likely to have changed during the past several years. METHODS: Data regarding clinical and laboratory features were abstracted retrospectively from medical records of 76 subjects with complicated parapneumonic effusions at a tertiary children's hospital from 1996 through 2001. Incidence rates per 10 000 hospital discharges and per 1000 patients with nonviral pneumonia were calculated. RESULTS: Etiologic organisms were Streptococcus pneumoniae (31 subjects), Staphylococcus aureus (7), Streptococcus pyogenes (5), Abiotrophia sp. (1) and no culture-confirmed agent (32). The annual incidence of complicated parapneumonic effusions per 10 000 discharges progressively increased from 4.5 in 1996 to 25.0 in 1999 (P = 0.0001), then declined to 10.1 in 2001 (P = 0.03). Similarly the incidence per 1000 cases of nonviral pneumonia increased from 2.9 in 1996 to 11.0 in 1999 (P = 0.003) and then declined to 4.8 in 2001 (P = 0.053). Whereas S. pneumoniae was the leading confirmed etiology in each year, the proportion of cases caused by Staphylococcus aureus increased from 6% in 1996 to 2000 (all of which were methicillin-susceptible) to 30% in 2001 (all methicillin-resistant; P = 0.04). CONCLUSIONS: The incidence of complicated parapneumonic effusions in children with community-acquired pneumonia increased from 1996 to 1999 and then declined concomitant with the introduction of the pneumococcal conjugate vaccine. Although cases caused by S. pneumoniae have decreased, community onset methicillin-resistant Staphylococcus aureus has emerged as a cause of pneumonia with complicated effusions in children.